The 57-word typed message, dated October 9, 1902 and signed by Bell, was for the inventor to invite Marconi to visit him at his home in Cape Breton, Nova Scotia.
The Bell-Marconi message is now expected to sell for up to £4000 at Bonhams in London on March 27, which coincides with the 165th anniversary of Bell’s birth in South Charlotte Street, Edinburgh, in 1847.